Merge email package 4.0 from the sandbox, including documentation, test cases,

and NEWS updates.

Lib/email/utils.py

@@ -0,0 +1,306 @@
+# Copyright (C) 2001-2006 Python Software Foundation
+# Author: Barry Warsaw
+# Contact: email-sig@python.org
+
+"""Miscellaneous utilities."""
+
+__all__ = [
+    'collapse_rfc2231_value',
+    'decode_params',
+    'decode_rfc2231',
+    'encode_rfc2231',
+    'formataddr',
+    'formatdate',
+    'getaddresses',
+    'make_msgid',
+    'parseaddr',
+    'parsedate',
+    'parsedate_tz',
+    'unquote',
+    ]
+
+import os
+import re
+import time
+import base64
+import random
+import socket
+import warnings
+from cStringIO import StringIO
+
+from email._parseaddr import quote
+from email._parseaddr import AddressList as _AddressList
+from email._parseaddr import mktime_tz
+
+# We need wormarounds for bugs in these methods in older Pythons (see below)
+from email._parseaddr import parsedate as _parsedate
+from email._parseaddr import parsedate_tz as _parsedate_tz
+
+from quopri import decodestring as _qdecode
+
+# Intrapackage imports
+from email.encoders import _bencode, _qencode
+
+COMMASPACE = ', '
+EMPTYSTRING = ''
+UEMPTYSTRING = u''
+CRLF = '\r\n'
+
+specialsre = re.compile(r'[][\\()<>@,:;".]')
+escapesre = re.compile(r'[][\\()"]')
+
+
+
+# Helpers
+
+def _identity(s):
+    return s
+
+
+def _bdecode(s):
+    # We can't quite use base64.encodestring() since it tacks on a "courtesy
+    # newline".  Blech!
+    if not s:
+        return s
+    value = base64.decodestring(s)
+    if not s.endswith('\n') and value.endswith('\n'):
+        return value[:-1]
+    return value
+
+
+
+def fix_eols(s):
+    """Replace all line-ending characters with \r\n."""
+    # Fix newlines with no preceding carriage return
+    s = re.sub(r'(?<!\r)\n', CRLF, s)
+    # Fix carriage returns with no following newline
+    s = re.sub(r'\r(?!\n)', CRLF, s)
+    return s
+
+
+
+def formataddr(pair):
+    """The inverse of parseaddr(), this takes a 2-tuple of the form
+    (realname, email_address) and returns the string value suitable
+    for an RFC 2822 From, To or Cc header.
+
+    If the first element of pair is false, then the second element is
+    returned unmodified.
+    """
+    name, address = pair
+    if name:
+        quotes = ''
+        if specialsre.search(name):
+            quotes = '"'
+        name = escapesre.sub(r'\\\g<0>', name)
+        return '%s%s%s <%s>' % (quotes, name, quotes, address)
+    return address
+
+
+
+def getaddresses(fieldvalues):
+    """Return a list of (REALNAME, EMAIL) for each fieldvalue."""
+    all = COMMASPACE.join(fieldvalues)
+    a = _AddressList(all)
+    return a.addresslist
+
+
+
+ecre = re.compile(r'''
+  =\?                   # literal =?
+  (?P<charset>[^?]*?)   # non-greedy up to the next ? is the charset
+  \?                    # literal ?
+  (?P<encoding>[qb])    # either a "q" or a "b", case insensitive
+  \?                    # literal ?
+  (?P<atom>.*?)         # non-greedy up to the next ?= is the atom
+  \?=                   # literal ?=
+  ''', re.VERBOSE | re.IGNORECASE)
+
+
+
+def formatdate(timeval=None, localtime=False, usegmt=False):
+    """Returns a date string as specified by RFC 2822, e.g.:
+
+    Fri, 09 Nov 2001 01:08:47 -0000
+
+    Optional timeval if given is a floating point time value as accepted by
+    gmtime() and localtime(), otherwise the current time is used.
+
+    Optional localtime is a flag that when True, interprets timeval, and
+    returns a date relative to the local timezone instead of UTC, properly
+    taking daylight savings time into account.
+
+    Optional argument usegmt means that the timezone is written out as
+    an ascii string, not numeric one (so "GMT" instead of "+0000"). This
+    is needed for HTTP, and is only used when localtime==False.
+    """
+    # Note: we cannot use strftime() because that honors the locale and RFC
+    # 2822 requires that day and month names be the English abbreviations.
+    if timeval is None:
+        timeval = time.time()
+    if localtime:
+        now = time.localtime(timeval)
+        # Calculate timezone offset, based on whether the local zone has
+        # daylight savings time, and whether DST is in effect.
+        if time.daylight and now[-1]:
+            offset = time.altzone
+        else:
+            offset = time.timezone
+        hours, minutes = divmod(abs(offset), 3600)
+        # Remember offset is in seconds west of UTC, but the timezone is in
+        # minutes east of UTC, so the signs differ.
+        if offset > 0:
+            sign = '-'
+        else:
+            sign = '+'
+        zone = '%s%02d%02d' % (sign, hours, minutes // 60)
+    else:
+        now = time.gmtime(timeval)
+        # Timezone offset is always -0000
+        if usegmt:
+            zone = 'GMT'
+        else:
+            zone = '-0000'
+    return '%s, %02d %s %04d %02d:%02d:%02d %s' % (
+        ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'][now[6]],
+        now[2],
+        ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
+         'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][now[1] - 1],
+        now[0], now[3], now[4], now[5],
+        zone)
+
+
+
+def make_msgid(idstring=None):
+    """Returns a string suitable for RFC 2822 compliant Message-ID, e.g:
+
+    <20020201195627.33539.96671@nightshade.la.mastaler.com>
+
+    Optional idstring if given is a string used to strengthen the
+    uniqueness of the message id.
+    """
+    timeval = time.time()
+    utcdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(timeval))
+    pid = os.getpid()
+    randint = random.randrange(100000)
+    if idstring is None:
+        idstring = ''
+    else:
+        idstring = '.' + idstring
+    idhost = socket.getfqdn()
+    msgid = '<%s.%s.%s%s@%s>' % (utcdate, pid, randint, idstring, idhost)
+    return msgid
+
+
+
+# These functions are in the standalone mimelib version only because they've
+# subsequently been fixed in the latest Python versions.  We use this to worm
+# around broken older Pythons.
+def parsedate(data):
+    if not data:
+        return None
+    return _parsedate(data)
+
+
+def parsedate_tz(data):
+    if not data:
+        return None
+    return _parsedate_tz(data)
+
+
+def parseaddr(addr):
+    addrs = _AddressList(addr).addresslist
+    if not addrs:
+        return '', ''
+    return addrs[0]
+
+
+# rfc822.unquote() doesn't properly de-backslash-ify in Python pre-2.3.
+def unquote(str):
+    """Remove quotes from a string."""
+    if len(str) > 1:
+        if str.startswith('"') and str.endswith('"'):
+            return str[1:-1].replace('\\\\', '\\').replace('\\"', '"')
+        if str.startswith('<') and str.endswith('>'):
+            return str[1:-1]
+    return str
+
+
+
+# RFC2231-related functions - parameter encoding and decoding
+def decode_rfc2231(s):
+    """Decode string according to RFC 2231"""
+    import urllib
+    parts = s.split("'", 2)
+    if len(parts) == 1:
+        return None, None, urllib.unquote(s)
+    charset, language, s = parts
+    return charset, language, urllib.unquote(s)
+
+
+def encode_rfc2231(s, charset=None, language=None):
+    """Encode string according to RFC 2231.
+
+    If neither charset nor language is given, then s is returned as-is.  If
+    charset is given but not language, the string is encoded using the empty
+    string for language.
+    """
+    import urllib
+    s = urllib.quote(s, safe='')
+    if charset is None and language is None:
+        return s
+    if language is None:
+        language = ''
+    return "%s'%s'%s" % (charset, language, s)
+
+
+rfc2231_continuation = re.compile(r'^(?P<name>\w+)\*((?P<num>[0-9]+)\*?)?$')
+
+def decode_params(params):
+    """Decode parameters list according to RFC 2231.
+
+    params is a sequence of 2-tuples containing (content type, string value).
+    """
+    new_params = []
+    # maps parameter's name to a list of continuations
+    rfc2231_params = {}
+    # params is a sequence of 2-tuples containing (content_type, string value)
+    name, value = params[0]
+    new_params.append((name, value))
+    # Cycle through each of the rest of the parameters.
+    for name, value in params[1:]:
+        value = unquote(value)
+        mo = rfc2231_continuation.match(name)
+        if mo:
+            name, num = mo.group('name', 'num')
+            if num is not None:
+                num = int(num)
+            rfc2231_param1 = rfc2231_params.setdefault(name, [])
+            rfc2231_param1.append((num, value))
+        else:
+            new_params.append((name, '"%s"' % quote(value)))
+    if rfc2231_params:
+        for name, continuations in rfc2231_params.items():
+            value = []
+            # Sort by number
+            continuations.sort()
+            # And now append all values in num order
+            for num, continuation in continuations:
+                value.append(continuation)
+            charset, language, value = decode_rfc2231(EMPTYSTRING.join(value))
+            new_params.append(
+                (name, (charset, language, '"%s"' % quote(value))))
+    return new_params
+
+def collapse_rfc2231_value(value, errors='replace',
+                           fallback_charset='us-ascii'):
+    if isinstance(value, tuple):
+        rawval = unquote(value[2])
+        charset = value[0] or 'us-ascii'
+        try:
+            return unicode(rawval, charset, errors)
+        except LookupError:
+            # XXX charset is unknown to Python.
+            return unicode(rawval, fallback_charset, errors)
+    else:
+        return unquote(value)